Field of the Invention
The present invention relates to a walk behind powered drive piece of outdoor equipment. More specifically, the present invention relates to a control system on a walk behind lawn mower wherein there is a pivoting handlebar that controls the speed of the lawn mower.
Description of Related Art
The walk behind rotary lawn mower is well known and consists of a wheeled housing and a generally U-shaped handle extending upwardly and rearwardly from the housing for pushing, guiding, and steering the lawn mower during use. Where the lawn mower is self-propelled the need to push the mower is eliminated and a variable speed can be utilized to match the speed of the mower to the walking pace of the individual user of the lawn mower.
Several approaches are known to control the speed of a walk behind self-propelled lawn mower. One method relies on pivoting a portion of the handle to control speed, doing away with the separate pivotal control bail. The lawn mower comprises multiple drive and driven plates which are separated when the clutch is disengaged, biasing the plates to separated positions wherein tilting the handle effects rotation of the drive wheel by applying variable pressure, so as to variably engage the clutch. This device is relatively difficult to use and has a large number of parts, leading to difficulty in keeping the device adjusted and in repair.
Another approach to variable speed walk behind lawn mowers involves a sliding handle grip wherein the handle is fixed to the mower housing such that it maintains a fixed angle of inclination, wherein the sliding motion pulls on a transmission cable that controls the ground speed. While this system is more recent and simpler in construction, it suffers from even more problems. Stopping the system for reverse action is slow or non-existent, since it can lock up the wheels or not stop fast enough. In addition, since the speed varies with grip, there can be accidents caused due to grip problems, such as not being able to let go fast enough. While walking, you must continuously push downward to operate the variable speed slide mechanism. This downward push makes the action unnatural. The rear wheels are locked upon stopping and, in order to make a 180 degree turn, it is not easy to prevent the wheels from spinning, as pushing down and forward is what lifts the front of the deck as well as engages the transmission.
While both of these types of systems are still in use to control ground speed, both are still somewhat unnatural to use in cutting the lawn. The safety issues around their use, their difficulty in smoothly controlling ground speed, as well as the jerky motion created while using these devices, has led many lawn mower users to shy away from the self-powered mowers with variable speed controlled by the user. Finding a better way to control ground speed in a continuous variable manner is still sought after by the industry.